Shielding design

T. Rockwell, 111, ed.. Reactor Shielding Design Manual, McGraw Hill Book Co., Inc., New York, 1956. 

CP-1 was assembled in an approximately spherical shape with the purest graphite in the center. About 6 tons of luanium metal fuel was used, in addition to approximately 40.5 tons of uranium oxide fuel. The lowest point of the reactor rested on the floor and the periphery was supported on a wooden structure. The whole pile was surrounded by a tent of mbberized balloon fabric so that neutron absorbing air could be evacuated. About 75 layers of 10.48-cm (4.125-in.) graphite bricks would have been required to complete the 790-cm diameter sphere. However, criticality was achieved at layer 56 without the need to evacuate the air, and assembly was discontinued at layer 57. The core then had an ellipsoidal cross section, with a polar radius of 209 cm and an equatorial radius of309 cm [20]. CP-1 was operated at low power (0.5 W) for several days. Fortuitously, it was found that the nuclear chain reaction could be controlled with cadmium strips which were inserted into the reactor to absorb neutrons and hence reduce the value of k to considerably less than 1. The pile was then disassembled and rebuilt at what is now the site of Argonne National Laboratory, U.S.A, with a concrete biological shield. Designated CP-2, the pile eventually reached a power level of 100 kW [22]. 

Medical X-Ray and Gamma-Ray Protection for Energies Up to 10 MeV— Structural Shielding Design and Evaluation (1970). [Superseded by NCRP Report No. 49]... 

THERMAL EFFECTS ATTENUATION. Shield designs are to also limit exposure of personnel to a critical heat flux value based on the total time of exposure. This value of heat flux is determined by the following equation ... 

Shields designed for accidental explosions only are designed to provide personnel protection from the MCI at that operation and may not, in all cases provide asset protection. 

SHIELD DESIGN. In the initial approach to operational shield design, the hydrostatic pressure that would result from the MCI in the shield is determined. For a high explosive detonated in a... 

The next factor in the shield design is to design for prevention of fragment penetration of the shield material. 

Fragment penetration can not only be a direct hazard to operating personnel, but partial penetration can weaken the shield causing subsequent failure from the overpressures. Fragment data and criteria for shield design to prevent penetration are contained in chapter 2 of reference 3 and in reference 4. 

SC 1-5 Uncertainty in Risk Estimates SC 1-6 Basis for the Linearity Assumption SC 1-7 Information Needed to Make Radiation Protection Recommendations for Travel Beyond Low-Earth Orbit SC 9 Structural Shielding Design and Evaluation for Medical Use of X Rays and Gamma Rays of Energies Up to 10 MeV SC 46 Operational Radiation Safety... 

Structural Shielding Design and Evaluation for Medical Use of X Rays and Gamma Rays of Energies Up to 10 MeV (1976) Environmental Radiation Measurements (1976)... 

Solid electrodes in unstirred solution. The most useful solid electrodes are platinum, gold, vitreous carbon, and carbon paste. The preferred configuration for theoretical work is a flat planar surface sealed in glass with epoxy or snugly fitted into a Teflon shroud. The electrodes ordinarily are unshielded, although shielded designs have been described.94... 

Several general classes of shield designs have been conceived. As shown in Figure 3, some have cylindrical or spherical configuration while others are rectangular frame and panel designs. 

The suppressive shield designs that we have been discussing are based on a major four-year technology development effort by organizations listed in Table VI. 

Studies have been conducted to develop a technological base for accurate determination of shield performance parameters. It was found early in the program that the available data base was inadequate for accurately predicting the blast, fire, and fragment effects that would occur as a result of an accidental detonation of an explosive in a shield environment. Indepth studies resulted in development of suppressive shield design procedures... 

Shield design optimization for the CF-SPT head shows that critical dimensions such as shield gap length and shield height are expected to be in the order of a few tens of nanometers, as shown in Fig. 8.12. It is difficult to realize such a small shield structure using normal head fabrication techniques. However, the fabrication of a shielded CF-SPT head by a unique process has been demonstrated [17]. This process is as follows a soft magnetic material is deposited on the head surface followed by focused ion bead (FIB) milling to form the shield gap, as depicted in Fig. 8.13. Improvement in writing resolution was actually obtained for the fabricated shield head. 

Mathe B (2003). Shielding design for a PET imaging suite a case study. Health Phys 84 S83... 

NMR imaging can be applied for different problems of network characterization. The following experiments were done with a VARIAN unity 200 MHz (wide bore) equipped with a homemade imaging probe of following specifications active-shielded design, maximum gradient 5 mT/cm RF part resonance frequency 67 MHz (deuterium), 200 MHz (protons) saddle coil or solenoid with different inner diameter (5 mm, 7 mm, and for deuterium coil 26 mm) temperature control between 0 °C and 120 °C. 

Table 10-4, SuuMABr of Shielding Design fob Different Configurations OF Source and Receptor (T)...

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